Post-hole digger.



C. W. GARRETT.

POST HOLE DIGGER.

APPLICATION FILED IIILY I1, I9I4.

Patented Aug. I, 1916.-

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CARRINGTON W. GARRETT, OF WASHINGTON, DISTRICT OF COLUMBIA.

POST-HOLE BIGGER.

Specification of Letters Patent.

Patented Aug. 1, 1916.

Application filed July 17, 1914. Serial No. 851,502. i

To all whom t may concern:

Be it known that I, CARRINGTON W. GAR'L Rn'rr, a citizen of the UnitedStates, residing .at Washington, in the District ofColumbia, haveinvented certain new and useful Improvements'in Post-Hole Diggers; and Ido hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which itV appertains to make and use the same. Y

This invention relates to post-hole diggers of the type utilizingendless belt excavators. An object in View is the provision of means foreconomical use of hand power for effecting a maximum of excavation witha minimum expenditure of energy.. y

A further object is the rendering of the parts simple and compact instructure and assemblage, for enabling handling and transv portation.

' With these and other objects in view, as will in part be stated and inpart become apparent, the invention comprises certain novelconstructions, combinations and arrangements of parts as willhereinafter become obvious.

In the accompanying drawing,,Figure 1 isa vertical, central sectiontaken longitudinally through an apparatus embodying the features of theinvention, intermediate portions being broken out for the .saving ofspace. Fig. 2 is a view in side elevation thereof. Fig. 3 is afragmentary, enlarged cross section taken on the plane indicated by line3 3 of Fig. 1 and looking downwardly. Fig. 4 is a fragmentary plan ofone of the frame guides. Y

Referring to the drawing by numerals, 1, 1 indicate the upright bars ofa 'frame which is completed by a block 2 fixed to .and connecting theupper ends of rods 1, and block 3 fixed to and connecting the lower endsof rods 1. Blocks 2 and '3 are prefer-Vv ably castings and are. rigidlyfixed to the rods 1 so as to form a rigid sustaining frame,

.which is arranged to slide vertically in a guiding frame consisting ofsupporting legs 4, 4, resting on the ground .and connected at theirupper ends to atable 5, the table having an annular L-plate connected bycross plates Gand 29. Plate 29 is provided with vertical, preferablyintegrahflanges 7 and a guiding aperture 8, one .aperture 8 being formedfor each rod 1, for guiding the sustaining frame in its movement andprevent- 'ing lateral or edgewise play thereof. Legs lplate 6 ordirectly engaging table 5.I Afbolt 5, extending through the table andthe oli'- set shoulder, completes vthe detachable connection of eachleg'with the table, and the legs are preferably braced by stays 9detachably connected to the respectivev legs and all detachablyconnected to acentral sleeve 10. Lateral brackets 9 are fixed to two ofthe stays 9, and each terminates in a sleeve 9 surrounding therespective rod 1 for cooperating with guiding apertures 8 in' guidingVthe sustaining frame in its vertical movement.

Block 2 carries a shaft 11, the projecting end portions of which formjournals for drums l2, 12, each of which s engaged by a conveyer belt13, of any appropriate type, but each consisting preferably of a pair ofendless sprocket chains extending-from the respective. drums` l12 to andabout correspending drums 14 arranged at the lower end of the sustainingframe and journaled on stub shafts 15 15, detachably fixed to the block3. Inview of the employment of sprocket chain belts, drums 12 and 14are, of course,'formed with appropriate sprocket teeth intermeshing withtheJ chains. Drums 14 are spaced. apart only a distance sufhcient toenable the extension of bars 1 therebetween without contact, .and thedrums are internally hollow to accommodate block 3 and gearing to bedescribed. The walls of the hollowed interior of each drum .are iiaredto form an incline 14 for dirt to roll down for automatically keepingthe interior of the drums clear during use. Each drum 14 may bejournaled directly on shaft 15, but preferably a beveled gear 16 isprovided for each shaft 15 and is ,formed with an axial sleeve 16journaled on the respective shaft. On the'extended portion of eachsleeve 16', the

respective drum 14 is keyed. Horizontally end is cylindrical and extendsthrough and is j oui-naled in block 8. The lower cylindrical portion ofshaft 18, below gear 17 and above block 8, is provided with an annularflange 18 resting upon thrust bearings 19, the latter being preferablyballs and confined by retainer ring 2G, the balls finding a raceway onthe up 3er portion of block 3. A. dust and dirt guard is provided forgears i 16 .and 17, and consists of a housing or casing 21 preferably ofsheet material. Each drum 1d, at its inner face, is formed with anannular flat portion or race-way 22, andV rollers 28, 211, carried byshaft 18 and disf Josed at diametricallv oanosite vmJoints of therace-ways engage the race-ways 22 for limiting tilting stresses andlateral play of rollers 14E.

Each drum 14 has its periphery provided with a number of radial diggerteeth 28, preferably having their free end portions bent .atvariousangles at different places about the periphery of the respectivedrums, so as to insure engagementof substantially all earth beneath thedrums by the teeth when the drums are revolved. As this stag-- geredrelation Lof the teeth terminals could not be accurately delineatedexcept by an extension and then only by a distortion of the curvedsurfaces of the peripheries of the drums, the staggered relation Yof theteeth terminals has been indicated by the dotted lines in Fig. 1.

Detachably fixed to the central portion of plates 6 and 29 is a. socketbearing 211 which is centrally apertured for free-ly accommodating shaft18, and a cone bearing 25 rides in socket 211 and is also centrallyapertured for free passage of shaft 18,. Cone 25 is detachably fixed toa beveled gear 26 which meshes with like gears 27 which latter are keyedto stub shafts 28 engaged by and adapted to be manually actuated bycrank 28. Each shaft 28 is ournaled at its inner end in a bracket 29fixed to the central portion of plate 29, and extending across table 5between gears 27, the plate 29 being appropriately apertured to Y freelyaccommodate shaft 18. The outer portion of each shaft 28 is journaled ina bracket 30 fixed to and upstanding from the respective side of thetable 5.

Cone bearing 25 has a central aperture of sufficient size to freelyaccommodate shaft 18, which, as seen in Fig. 8, is sqiraredV at theplaces of engagement of cone '25, and, to eliminate friction due torelative movement of the shaft, cone 25 is provided with rounded lateralrecesses opening into the central aperture and disposed to receiveroller bearings 25, there being one roller 25 for each side of shaft 18.As the rollers 25 are confined against longitudinal movement rela--tiveJ to either the cone or the shaft, the shaft must rotate when thecone is rotated, and

yet the shaft is yfree for vertical, longitudinal movement with aminimum of friction.

Each endless belt carries a series of elevator buckets 81 of a size tobe accommodated between the rows of teeth 28, and a spring 82 is fixedto block 2 with its end portions extending into the path of the innerends of buckets 31 so that, in operation, the buckets strike the springand sufficient vibration is imparted to the buckets as they pass overdrums 12 to insure discharge of the contents of the buckets as they passover the respective drums, the angle ofthe buckets being such at thetime of the discharge as to insure falling of the discharged dirtoutside of the excavation being made.

The operation is believed to be obvious, but may be briefly stated,consisting merely of manually or otherwise rotating shafts 28 in adirection causing travel of the endless conveyer belts 18 in thedirection indicated by the arrow in Fig. 2. Drums 111 are therebyrevolved through power transmitted through shaft 18 and gears 17 and 16,so that the teeth 28 loosen the dirt and the buckets remove it. As thiscontinues, the drums descend along with the sustaining frame and partssustained thereby. Bars 1 and shaft 18 are guided in their verticaldescent and thus insure straight downward movement of the drums and aresulting vertical posthole. 1

What 1 claim is 1. 1n a post-hole digger, the combination of uprightyrods and upper and lower blocks fixed thereto, a retaining frame havingvertically disposed sleeves surrounding and guiding said rods, a shaftjournaled in the blocks, a drum rotatably carried by the lower block, adrum rotatably carried by the upper block, an endless-conveyer beltoperatively extended about the drums, excavating means projecting fromthe lower drum, means for rotating the shaft, means for transmittingmovement from the shaft to the lower drum, and conveying means carriedby the belt.

2. 1n a post-hole diggenthe combination of a vertically shiftablesustaining frame, a retaining frame guiding the sustaining frame in itsmovement, a squared shaft journaled in the sustaining frame andshiftable longitudinally therewith, a bearing member sustained by theretaining frame and having an aperture through which the shaft isadapted to move, said bearing having recesses laterally of the shaft,roller bearings vin said recessesvcontacting with the faces of the shaftand confined against longitudinal movement relative to the bearingmember, means for revolving the bearing member, and excavating meansdriven by the shaft.

Y 3. 1n a post-hole digger, a vertically movable sustaining frame, meansguiding the frame in itsV movement, a shaft ournaled in 130 the frame,means for rotating the shaft, a. pair of drums disposed on oppositesides of the shaft, gearing actuated by the shaft for driving the drums,and rollers Carried by the shaft and engaging the inner ends of theydrums for steadying movement thereof.

4. In a post-hole digger, excavating rollers internally hollow andhaving their interior walls flaring to provide inclines down which dirtis adapted to move to be discharged from within the rollers, and drivingmeans for the rollers within the hollow portions thereof.

5. In a post-hole digger, the combination of guiding rods, means forguiding the rods,

Copies of this patent may be obtained for a block fixed to the rods,shafts Xed to the block, a gear wheel journaled on each shaft, anactuating shaft journaled in the block, a gear wheel actuated by saidlast-named shaft and meshing with the first-named gear wheels, and drumsiXed to the rst-named gear wheels and substantially inclosing all of thegear wheels.

In testimony whereof I afix my signature in presence of two witnesses.

CARRING'ION W. GARRETT.

Witnesses:

N. CURTIS LAMMOND, EDGAR M. KITGHIN.

ve cents each, by addressing the Commissioner of Patents, Washington, D.C.

